Question

Have you ever broken a bone? After reading this chapter, you should understand how that bone healed. What are the steps in the repair of broken bones? How is this process similar to or different from the normal growth of a bone?

We will focus on bones in this discussion. How do bones grow? How do they heal? What kinds of cells are involved in these processes?

Answer 1

Bone remodeling is a repair process, in which the damaged osseous tissue is replaced with the new tissue before its deterioration. Osteoblasts initiate the process of bone calcification. Osteoblasts initiate the process of bone calcification, and they are embedded within the extracellular matrix secreted by them, and they become osteocytes (matured bone cells). Osteocytes are deposited on the periosteum and increase bone density, thus improve the bone strength.

The rate of bone formation and breakdown changes with age. New osseous tissue that is formed during the process of bone remodeling is stronger than the old bone. And during this process, the extracellular matrix redistributes along the lines of mechanical stress, so the areas receiving more stress become stronger. So, the bone remodeling process is essential in adulthood.

And during this process, the shape of the bones may change according to the stress felt by them. For example, in osteoporosis patients, backbone (of the vertebra) may be compressed due to stress and may reduce their height; similarly the shaft (diaphysis) of long bones also.